Generation Of 3D City Models From Airborne Laser Scanning Data

Airborne laser scanners enable the geometric acquisition of the terrain surface, including objects like trees or buildings which rise from the terrain. Even though for a number of applications a so{called Digital Surface Model (DSM) representing the surface geometry by an object independent distribution of points is su cient, the further quali cation of the original scanner data is necessary for more sophisticated tasks like visualizations or high quality 3D simulations. In order to obtain a 3D city model, which is more suitable for these applications, an abstraction and interpretation of the surface model is required, e.g. buildings have to be separated from the terrain surface and represented by 3D CAD-like description. Due to the very pretentious problem of automatic interpretation of height or range data, optimal results can only be achieved by using supplementary sources of information. Within the approach presented in this paper the segmentation of planar surfaces from the DSM, which is a prerequisite for the 3D reconstruction of the buildings, is supported by given ground plans. This type of information frequently is already available from a 2D Geo Information System (GIS). By introducing this type of information into the segmentation process the very high demands on the spatial resolution and quality of the DSM can additionally be reduced. The 2D building outlines are also used during the reconstruction step by deriving hypotheses on the possible roof shapes. This enables the combination of the segmented planes in order to obtain a 3D boundary representation of the building.